Display device and transmission device

Abstract

A display device comprising: a reception unit; a display unit; a storage unit; and an acquisition unit. The reception unit receives a stream containing a plurality of video frames and first display timing information specifying a display timing of each video frame. The display unit displays each video frame at a corresponding display timing specified by the first display timing information. The storage unit stores an image and second display timing information specifying a display timing of the image. The acquisition unit acquires correction information specifying a correction amount for correcting the display timing of the image and thereby enabling the image to be displayed in synchronization with the video frames displayed by the display unit. The display unit further displays the image at a corrected display timing determined by correcting the display timing of the image by using the correction amount specified by the correction information.

1 . A display device that receives a stream containing a plurality of video frames, separately acquires and stores therein an image, and displays the received stream and the acquired image in synchronization, the display device comprising:
 a reception unit that receives a stream containing a plurality of video frames and first display timing information, the first display timing information specifying a display timing of each of the video frames;   a display unit that displays each of the video frames at a corresponding display timing specified by the first display timing information;   a storage unit that stores an image and second display timing information specifying a display timing of the image; and   an acquisition unit that acquires correction information specifying a correction amount for correcting the display timing of the image and thereby enabling the image to be displayed in synchronization with the video frames displayed by the display unit, wherein   the display unit displays the image at a corrected display timing determined by correcting the display timing of the image by using the correction amount specified by the correction information, whereby the image is displayed in synchronization with the video frames.   
     
     
         2 . The display device of  claim 1 , wherein
 the stream further contains the correction information, and   the acquisition unit acquires the correction information from the stream.   
     
     
         3 . The display device of  claim 2 , wherein
 the display unit comprises a display and displays the video frames and the image on the display, and   the display unit superimposes the image onto each of the video frames when displaying the video frames and the image on the display.   
     
     
         4 . The display device of  claim 3  further comprising
 a sub-reception unit that receives a stream containing a plurality of video frames and information indicating a display timing, wherein 
 the storage unit stores the plurality of video frames received by the sub-reception unit as the image, and 
 the storage unit stores the information received by the sub-reception unit as the second display timing information, the second display timing information thus specifying a display timing of each of the video frames received by the sub-reception unit. 
 
     
     
         5 . The display device of  claim 4 , wherein
 the reception unit comprises a broadcast wave reception unit that receives broadcast waves transmitted by a broadcast station for transmitting data, and the sub-reception unit comprises a transmission signal reception unit that receives transmission signals transmitted from an external network for transmitting data, and   the stream received by the reception unit is a stream carried on the broadcast waves received by the broadcast wave reception unit, and the stream received by the sub-reception unit is a stream carried on the transmission signals received by the transmission signal reception unit.   
     
     
         6 . The display device of  claim 5 , wherein
 the stream carried on the broadcast waves and the stream carried on the transmission signals are each a stream in the Moving Picture Experts Group (MPEG)-2 transport stream (TS) format.   
     
     
         7 . The display device of  claim 1  further comprising
 a sub-reception unit that receives a stream containing a plurality of video frames and information indicating a display timing, wherein 
 the storage unit stores the plurality of video frames received by the sub-reception unit as the image, 
 the storage unit stores the information received by the sub-reception unit as the second display timing information, the second display timing information thus specifying a display timing of each of the video frames received by the sub-reception unit, 
 the stream received by the reception unit and the stream received by the sub-reception unit are each a stream in the MPEG-2 TS format, 
 the display unit comprises:
 a first decoder that reconstructs a video frame from the stream received by the reception unit; 
 a second decoder that reconstructs a video frame from the stream received by the sub-reception unit; 
 a first arrival time counter that appends, to the stream received by the reception unit, information that indicates a first arrival time pertaining to a timing at which the stream received by the reception unit is to be input to the first decoder; 
 a second arrival time counter that appends, to the stream received by the sub-reception unit, information that indicates a second arrival time pertaining to a timing at which the stream received by the sub-reception is to be input to the second decoder; and 
 a delay input unit that, by using the first arrival time and the second arrival time, inputs the stream received by the sub-reception unit to the second decoder at a delayed timing that is later by a predetermined time period than a timing at which the stream received by the reception unit is input to the first decoder, and 
 
 the second decoder outputs the video frame reconstructed from the stream received by the sub-reception unit at an output timing such that the video frame reconstructed by the second decoder is displayed by the display unit at the corrected display timing. 
 
     
     
         8 . The display device of  claim 7  further comprising
 a multiplexer that generates a stream by multiplexing the video frame reconstructed by the first decoder and the video frame reconstructed by the second decoder. 
 
     
     
         9 . The display device of  claim 1  further comprising
 a sub-reception unit that receives a stream containing a plurality of video frames and information indicating a display timing, wherein 
 the storage unit stores the plurality of video frames received by the sub-reception unit as the image, 
 the storage unit stores the information received by the sub-reception unit as the second display timing information, the second display timing information thus specifying a display timing of each of the video frames received by the sub-reception unit, 
 the stream received by the reception unit and the stream received by the sub-reception unit are each a stream in the MPEG-2 TS format, 
 the display unit comprises:
 a first decoder that reconstructs a video frame from the stream received by the reception unit; 
 a second decoder that reconstructs a video frame from the stream received by the sub-reception unit; 
 an arrival time counter that appends, to the stream received by the reception unit, information that indicates a first arrival time pertaining to a timing at which the stream received by the reception unit is to be input to the first decoder, and appends, to the stream received by the sub-reception unit, information that indicates a second arrival time pertaining to a timing at which the stream received by the sub-reception is to be input to the second decoder; and 
 a delay input unit that, by using the first arrival time and the second arrival time, inputs the stream received by the sub-reception unit to the second decoder at a delayed timing that is later by a predetermined time period than a timing at which the stream received by the reception unit is input to the first decoder, and 
 
 the second decoder outputs the video frame reconstructed from the stream received by the sub-reception unit at an output timing such that the video frame reconstructed by the second decoder is displayed by the display unit at the corrected display timing. 
 
     
     
         10 . The display device of  claim 1  further comprising
 a sub-reception unit that receives a stream containing a plurality of video frames and information indicating a display timing, wherein 
 the storage unit stores the plurality of video frames received by the sub-reception unit as the image, 
 the storage unit stores the information received by the sub-reception unit as the second display timing information, the second display timing information thus specifying a display timing of each of the video frames received by the sub-reception unit, 
 the stream received by the reception unit and the stream received by the sub-reception unit are each a stream in the MPEG-2 TS format, 
 the display unit comprises:
 a first decoder that reconstructs a video frame from the stream received by the reception unit; and 
 a second decoder that reconstructs a video frame from the stream received by the sub-reception unit, and 
 
 the second decoder outputs the video frame reconstructed from the stream received by the sub-reception unit at an output timing such that the video frame reconstructed by the second decoder is displayed by the display unit at the corrected display timing. 
 
     
     
         11 . The display device of  claim 1  further comprising
 a sub-reception unit that receives a stream containing a plurality of video frames and information indicating a display timing, wherein 
 the storage unit stores the plurality of video frames received by the sub-reception unit as the image, 
 the storage unit stores the information received by the sub-reception unit as the second display timing information, the second display timing information thus specifying a display timing of each of the video frames received by the sub-reception unit, 
 the stream received by the reception unit and the stream received by the sub-reception unit are each a stream in the MPEG-2 TS format, 
 the display unit comprises:
 a first decoder that reconstructs a video frame from the stream received by the reception unit; 
 a second decoder that reconstructs a video frame from the stream received by the sub-reception unit; 
 a first arrival time counter that appends, to the stream received by the reception unit, information that indicates a first arrival time pertaining to a timing at which the stream received by the reception unit is to be input to the first decoder; 
 a second arrival time counter that appends, to the stream received by the sub-reception unit, information that indicates a second arrival time pertaining to a timing at which the stream received by the sub-reception is to be input to the second decoder; and 
 a delay input unit that, by using the first arrival time and the second arrival time, inputs the stream received by the sub-reception unit to the second decoder at a delayed timing that is later by a predetermined time period than a timing at which the stream received by the reception unit is input to the first decoder, and 
 
 the second decoder outputs the video frame reconstructed from the stream received by the sub-reception unit at an output timing such that the video frame reconstructed by the second decoder is displayed by the display unit at the corrected display timing, the second decoder outputs the video frame reconstructed from the stream received by the sub-reception unit at the output timing by using (i) the correction amount, (ii) a first reference time axis time, on a reference time axis, corresponding to the first arrival time, and (iii) a second reference time axis time, on the reference time axis, corresponding to the second arrival time. 
 
     
     
         12 . The display device of  claim 1 , wherein
 the image is a computer graphics image, and   the display unit comprises:
 a decoder that reconstructs video frames from the stream; and 
 an image output unit that outputs the computer graphics image at an output timing such that the computer graphics image is displayed by the display unit at the corrected display timing. 
   
     
     
         13 . A transmission device comprising:
 a video storage unit that stores a plurality of video frames;   a generation unit that generates a stream by multiplexing:
 the video frames stored in the video storage unit; 
 first display timing information specifying a display timing of each of video frames; and 
 correction information specifying a correction amount for causing an external device, storing second display timing information specifying a display timing of an image, to correct the display timing of the image and thereby display the image at a corrected display timing so as to be displayed in synchronization with the video frames, the corrected display timing determined by correcting the display timing of the image by using the correction amount specified by the correction information; and 
   a transmission unit that transmits the stream to the external device.